Synthesis of tetrahydro-β-carbolines from 2-indolylmethyl azides and propargylic alcohols.

A facile and efficient route to tetrahydro-β-carbolines from 2-indolylmethyl azides and propargylic alcohols via acid-catalyzed dehydrative annulation reactions is described. This reaction proceeds through a cascade sequence of Friedel-Crafts-type alkylation followed by intramolecular "Click" reaction, involving the formation of multiple chemical bonds in a single operation with excellent atom-economy and broad functional group tolerance.